Table of content

What is this :grey_question:

The rules of the game are explained in my original post.

27th Challenge

Challenge

I have never part taken in Advent of Code. This year I might. To get used to the idea I’m solving last year’s second challenge. Solve AoC day 2 2020. This is the second part which adds some more generic-ness to the orignal challenge posted yesterday.

Solution :white_check_mark: 

	fn main() {
	    let answer1 = INPUT.lines()
	        .filter(|&x| Entry::new(x).check_sled_rental())
	        .count();

	    let answer2 = INPUT.lines()
	        .filter(|&x| Entry::new(x).check_toboggan_rental())
	        .count();

	    println!("answer1:{} answer2:{}",answer1,answer2);
	}

	struct Entry {
	    left:usize,
	    right:usize,
	    letter:char,
	    password:String,
	}

	impl Entry{

	    fn check_toboggan_rental(&self) -> bool {
	        self.password.chars().nth(self.left - 1).unwrap().eq(&self.letter) ^
	            self.password.chars().nth(self.right -1 ).unwrap().eq(&self.letter)
	    }

	    fn check_sled_rental(&self) -> bool {

	        let num = self.password
	            .chars()
	            .filter(|c| c.eq(&self.letter))
	            .count();

	        num >= self.left && num <= self.right
	    }

	    fn new(line:&str) -> Entry{

	        let mut s:Vec<&str> = line
	            .split(' ')
	            .collect();

	        let range = s
	            .remove(0)
	            .split_once('-')
	            .unwrap();

	        let min:usize = range
	            .0
	            .parse()
	            .unwrap();

	        let max:usize = range
	            .1
	            .parse()
	            .unwrap();

	        let letter = s
	            .remove(0)
	            .trim_end_matches(":")
	            .chars()
	            .nth(0)
	            .unwrap();

	        let password = s.remove(0);

	        Entry{ left: min, right: max, letter, password: String::from(password) }
	    }
	}



	const INPUT:&str = "1-3 a: abcde
	1-3 b: cdefg
	2-9 c: ccccccccc";

To see the full source see github and see the live demo in playground.